Dwingeloo Radio Telescope | CAMRAShttps://www.camras.nl
C.A. Muller Radio Astronomy Station | PI9CAMFri, 22 Feb 2019 09:04:05 +0000en-UShourly1https://wordpress.org/?v=5.0.3Kick-off ‘COGITO in Space’ videoshttps://www.camras.nl/en/blog/2019/kick-off-cogito-in-space-videos/
Wed, 13 Feb 2019 17:00:15 +0000http://www.camras.nl/?p=5976The kick-off ‘COGITO in Space’ on November 5, 2018, marked the first public performance of the interdisciplinary ‘COGITO in Space’ project in ASTRON and at the Dwingeloo Radio Telescope. Speakers at the symposium in ASTRON’s Van de Hulst Auditorium were Frank White (The Overview Effect), Fred Spier (Big History and the Future of Humanity) and Nicole Stott (interview with the retired NASA astronaut). The symposium was moderated by Josephine Bosma. The symposium was continued in the radio telescope by sending brain activity from a visitor into the cosmos.

The symposium-part and the radio telescope-part of the COGITO project were filmed by Sandro Bocci. Special thanks to ASTRON (www.astron.nl) and CAMRAS. ‘COGITO in Space’ is a project by media artist Daniela de Paulis (www.cogitoinspace.org).

In the fold menus below, you can choose a video of the COGITO in Space project. Once a fold menu topic is opened you can click on the picture to open the film registration of that topic.

‘COGITO in Space’ Symposium PART 1

‘COGITO in Space’ Symposium PART 1

Speakers: Frank White (The Overview Effect) and Fred Spier (Big History and the Future of Humanity).

‘COGITO in Space’ symposium PART 2

‘COGITO in Space’ symposium PART 2

Speaker: Nicole Stott (interview with the retired NASA astronaut).

‘COGITO in Space’ Dwingeloo Radio Telescope

‘COGITO in Space’ Dwingeloo Radio Telescope

The ‘COGITO in Space’ project is staged at the Dwingeloo Radio Telescope in The Netherlands. A visitor in the cabin of the radio telescope sends her or his brain activity into the cosmos while viewing an immersive video of an experimental interpretation of the Earth as seen from Space. The visitor is fitted with a sophisticated encephalogram (EEG) system and a virtual reality headset; the preparation is carried by three neuroscientists Guillaume Dumas, Robert Oostenveld and Stephen Whitmarshand and takes approximately fifteen minutes. Once the preparation is completed, in real time the brain activity is converted into sound and transmitted into space by the artist Daniela De Paulis, using the antenna of the Dwingeloo Radio Telescope pointing in standstill. The brain activity is thus transmitted across a large portion of the sky, without a specific target, highlighting the Earth’s rotation and our place in the cosmos while the experience takes place. Before entering the cabin and transmitting their brain waves into space, visitors are guided by a planetary scientist to explore the area surrounding the scientific facilities. The naturalistic visit is based on principles of Big History and aims at inspiring in the visitors a stronger sense of connection with the Earth’s habitat, before symbolically leaving the planet.

]]>New photo of Lunar farside and Earthhttps://www.camras.nl/en/blog/2019/new-photo-of-lunar-farside-and-earth/
Tue, 05 Feb 2019 13:08:33 +0000http://www.camras.nl/?p=5942On Monday 4th February 2019, the Dwingeloo telescope downloaded a new photo of Earth and the lunar farside. This photo, taken Sunday 3rd February 2019 at 15:20 UTC, shows the lunar farside and Earth (with South America in view). The lunar farside has more visible craters than the side of the Moon which faces Earth.

This photo was taken by the Chinese satellite LongJiang 2 in a lunar orbit. One of the devices on this satellite was made by students from the Chinese Harbin Institute of Technology. They put a (relatively) simple webcam on it that can take pictures on command. These photos are then sent to Earth with a little antenna. Because the satellite is so far away, receiving the signal requires a large radio antenna. The Chinese have asked the CAMRAS volunteers at the Dwingeloo Radio Telescope to help with this. Downloading this photo from the satellite to the Dwingeloo Telescope (16 KB in size) took 20 minutes.

The little Chinese satellite that took this photo has been in lunar orbit since the beginning of 2018. It ‘took a ride’ on the rocket that launched the bigger QueQiao satellite. That satellite also hosts antennas from ASTRON, the original owner and professional neighbour of the Dwingeloo Radio Telescope. ASTRON hopes to use the antennas on the big satellite to receive signals from just after the Big Bang as part of the Netherlands-China Low-frequency Explorer (NCLE) project.

The amateur radio payload that took this picture was developed at the Harbin Institute of Technology by Mingchuan Wei (BG2BHC), Hu Chaoran (BG2CRY), Tai Mier (KG5TEP), Zhao Yuhao (BG2DGR). Taking this photo was coordinated by Wei. While downloading this picture, the CAMRAS Dwingeloo Radio Telescope was operated by Cees Bassa, Tammo Jan Dijkema and Vanessa Moss. The commands were uplinked to the satellite by German radio amateur Reinhard Kuehn (DK5LA) with his home-built yagi array. See more details in blog post Our precious Earth and the lunar far side.

The photo has been color-corrected. Since the satellite camera lacks an infrared filter, colors come out too red. The original is below; we edited it to balance the colors, and make the Moon greyscale.

In October 2018, the Dwingeloo Telescope also cooperated in receiving a lunar farside photo (see blog post Our precious Earth and the lunar far side) and even a time-lapse showing the Earth disappear behind the Moon (see blog post Time-laps of the Earth appearing behind the Moon). At that time, the satellite was closer to the Moon, so the entire Moon did not fit in the picture. In the next months, we expect to receive more of these photos. But in August 2019, this adventure will end: then LongJiang 2 will crash in a controlled manner onto the lunar surface in a controlled manner. QueQiao will continue operating for the foreseeable future.

Observing meteors

During our special openings and stargazing evenings, dozens of visitors are interested in observing meteors. This is why CAMRAS volunteers Simon Bijlsma (PA7SB) and Frans de Jong (PE1RXJ) have put more information on the astronomy page for those who want to read it again or want to know more. It concerns four articles:

Antenna building
Observing meteors with radio
Visualize radio meteors
Software Defined Radio receiver

We previously wrote those articles in Dutch for the website of the KNVWS Working Group Meteors. The articles are about observing meteor scatter with a self-built antenna in combination with an RTL SDR dongle and suitable software and visualizing and counting meteors with the SpectrumLab program. The aforementioned articles are here on the CAMRAS website in both Dutch and English,

Who is not such a self-builder or lacks the time needed to build a meteor scatter receiving station can of course also use our online CAMRAS webSDR receiver that is specially designed to receive real time meteor scatter with your own tablet, laptop, smartphone or computer.

CAMRAS volunteer Pieter-Tjerk de Boer (PA3FWM) designed this beautiful webSDR software already ten years ago. At the Amateur Radioclub of the University of Twente, his own UT webSDR receiver runs for the entire short wave spectrum from 0.1 to 30 MHz.

The CAMRAS webSDR for receiving meteor reflections was set up after a successful experiment in 2011 in which we streamed live meteor reflections over the internet for the first time during the maximum of the Perseids meteor shower. As a result, Simon Bijlsma has built the 2-meter and 6-meter Yagi antennae that are now used for the CAMRAS webSDR. The building description can be found in article 1. These antennae are linked to two RTL SDR dongles which then provide the CAMRAS webSDR stream with the help of the SDR software.

With the webSDR tuning to the frequency of the French Space radar GRAVES gives the possibility to observe aircraft and the ISS in addition to meteor reflections. Even echoes of the GRAVES radar that are reflected by the Moon are regularly seen! The distance to the Moon back and forth is about 800,000 km and the Moon is also a very bad reflector for radio waves, so most of the signal is lost. Nevertheless, the echoes are so strong that they can be clearly seen on the webSDR receiver. See above image with meteors (hook-shaped), aircraft (lines in the middle), ISS (slanted dotted line) and the moon (vertical dotted line).

Observing satellites

Recently, the webSDR has been expanded with a receiver for a Chinese moon satellite. The Dwingeloo telescope is one of the official reception ground stations for the Chinese moon satellite DSLWP-B. From Germany the uplink command signals are sent to the satellite. This satellite floats in an elliptical orbit around the moon, through which the satellite can also take pictures of the back of the moon. This is not possible from the earth. However, the nominal transmit power of this satellite is very limited and, depending on the mode used, only 1 to 2 Watt (30 – 33 dBm).

The 25m Dwingeloo telescope is used to receive the lunar photos and telemetry signals, the frequencies used in the 70cm band are 435.4 MHz and 436.4 MHz. The beautiful photos (see above) of the back of the moon and the earth can be found elsewhere on this website. Worldwide there is great interest among radio amateurs for the photos and telemetry signals of this satellite. In collaboration with Pieter Tjerk de Boer, Simon Bijlsma therefore connected a third RTL SDR dongle and connected it to the 70cm antenna of the telescope. This allows our many (international) visitors to the webSDR to follow the satellite signals in real time and decode the GMSK and FT4G signals themselves when the telescope follows the satellite.

The radio telescope is open on Saturday night, January 12, from 18:00 to 22:00.

In clear weather there are optical telescopes for stargazing next to the large radio telescope and we tell you about the stars that can be seen there.
In the radio telescope we continuously give demonstrations of a pulsar (neutron star) and/or hydrogen in the Milky Way.
The demonstration in the radio telescope always goes on, even in cloudy weather, because radio waves go right through the clouds.
In the Muller House, presentations of about a quarter of an hour are given and a demonstration of meteor scatter.
The program is similar to the CAMRAS program of the National Stargazing Days and the Dark-sky Night.

For access in the radio telescope we ask € 2 and for youth € 1. It is not possible to pay with pin.
Stargazing outside and listening to the presentations in the Muller House is free for everyone.

Tip: take a flashlight with you, but close to the stargazers use it moderately and preferably covered with red cellophane.

The radio telescope is easily accessible by bike; the car can be parked at the Staatsbosbeheer parking lot; from there it is about 15 minutes walk to the telescope.

The reason for this extra opening is the 100th anniversary of the International Astronomical Union (IAU). To commemorate this, it is celebrated worldwide for a year with all sorts of activities.
The birthday IAU100 starts in January 2019 with a long weekend stargazing: 100 Hours of Astronomy, four days and nights, from 10-13 January 2019, with amateur and professional astronomers, lovers of astronomy and the general public to share their knowledge and enthusiasm for the Universe.

]]>EUCARA 2018 conference reporthttps://www.camras.nl/en/blog/2018/eucara-2018-conference-report/
Thu, 22 Nov 2018 19:48:34 +0000http://www.camras.nl/?p=4069On Saturday 15 and Sunday 16 September, the third European conference on Amateur Radio Astronomy, EUCARA 2018, took place at the Astropeiler Stockert Radio Telescope in Germany. There we received a warm hospitality from the Stockert volunteers. There were 59 participants from 8 different countries, including Belgium, Denmark, Germany, the Netherlands, Slovenia, Sweden, the United Kingdom and the United States.

From CAMRAS the following volunteers participated: Paul Boven, Simon Bijlsma, Frans de Jong, Jan van Muijlwijk and Harm Munk. Some were accompanied by their partner.

Eleven participants gave presentations about their astronomy projects. Frans and Simon gave a lecture about the development of the meteor scatter webSDR and the detection results with this webSDR receiver. Paul gave a presentation on the new frontend in development of the Dwingeloo Radio Telescope and on VLBI with the Dwingeloo Radio Telescope.

On Saturday afternoon there was an excursion to the nearby gigantic 100-meter Effelsberg Radio Telescope and the adjacent LOFAR field.

On Saturday evening the day was evaluated while enjoying a conference dinner and ideas were exchanged about the common hobby of amateur radio astronomy.

On Sunday, Prof. Dr. Michael Kramer from the Max Planck Institute for Radio Astronomy gave a lecture on Einstein’s general theory of relativity and how the astronomers at the Max Planck Institute today use these insights to explain the phenomena observed in the universe, such as gravitational waves, black holes and neutron stars.

The Sunday afternoon was reserved for a personal meeting between the participants and the Stockert volunteers and to enjoy the beautiful weather and the view of the beautiful landscapes in the Eifel.

Worth mentioning is the impressive poster session of Stockert: with several tiny antennas and the Adalm SDR set they were able to detect hydrogen in the Milky Way.

On Monday November 5, the latest art project of Daniela De Paulis ‘COGITO in Space’ was launched in the Van der Hulst auditorium of ASTRON and the Dwingeloo Radio Telescope. There were about fifty guests, consisting of interested parties, acquaintances, artists and funding bodies. With the project COGITO ‘in space’, thoughts are spread in space like radio waves.

COGITO is an interdisciplinary, collaborative project and the result of several years of research at the Dwingeloo Radio Telescope and ASTRON. COGITO is a conceptually complex art project inspired by the Overview Effect. The main idea behind COGITO is to create a connection between the observer’s mind and his or her idea of the universe, while watching a fascinating video of the Earth as seen from space.

– Morning program

With a warm welcome, Frans de Jong (CAMRAS chairman) opened the morning program in the auditorium: a mini-conference with The Overview Effect as the main theme. The Overview Effect concerns the shift in self-awareness that astronauts experience as a result of seeing the Earth from space. Josephine Bosma (art critic) moderated the four parts of the program.

1. The mini-conference started with a strong opening and an inspiring lecture by Frank White (sociologist and political scientist), author of the book The Overview Effect: Space Exploration and Human Evolution. Frank considers himself a space philosopher. He highlighted various angles with keen headscratchers like: ‘Are we going to space or are we already there and just going a little bit further? What do we get out of space and what do we leave behind? Are we leaving the Earth in the distant future or are we just looking for expansion?’

2. Fred Spier (cultural anthropologist and social historian), author of the book Big History and the future of Humanity, addressed in his lecture his personal experiences during the flight of Apollo 8. ‘During that mission, the famous photo ‘Earth rise’ was taken, which shows planet Earth from above the lunar surface. This evoked a great deal of sentiment from the audience in the United States, with a strong awareness that we are looking at ourselves. In Europe, it was hardly mentioned in the news and the publication was dismissed as a nice picture. How did this difference arise?’

3. Then, Nicole Stott (aquanaut, astronaut and aquarellist in space) took the stage, speaking through a Skype-connection. Now retired, she has actually experienced the overview effect with an impact that she still carries with her. What follows is an interesting interview between her, Josephine and Daniela.

4. The mini-conference was concluded with a forum consisting of Daniela and the three neuroscientists Guillaume Dumas, Robert Oostenveld and Stephen Whitmarsh, who are involved in the development of COGITO.

The many questions and answers were informally continued in animated conversations during the lunch.

– Afternoon program

For the afternoon program, the guests were split into two groups.

a. In the auditorium one group participated in a lecture by Frans about the history and restoration of the Dwingeloo Radio Telescope and the current use by the CAMRAS foundation. Images and sound of the brain waves transmitted from the radio telescope were also streamed to the auditorium.

b. The group of guests with the parallel program first walked across the heath of the Dwingelderveld under the guidance of Maarten Roos (planetary scientist and filmmaker), while he told a story based on the book by Fred Spier. ‘For the walkers, the free field of view over the heathland symbolizes the emptiness in space and the 25-meter dish represents the Earth.’

After they arrived at the telescope, Roy Smits (astronomer and CAMRAS volunteer) told them about the origin of radio astronomy and the Dwingeloo Telescope. Afterwards, the guests climbed the metal stairs to the observation room and the big moment was finally there.

Daniela, the three neuroscientists and the telescope operators Jan van Muijlwijk and Michael Sanders (both CAMRAS volunteers) welcomed them wholeheartedly.

‘The cabin, converted into the art project ‘COGITO in Space’, is full of computers, a beamer and transmitting equipment. The remaining space is filled with stairs arranged around the ‘zero gravity chair’, which seems to give you weightlessness. A participant is already ready on this deckchair. She wears an EEG cap that measures her brain waves. Through a virtual reality headset, she gets to see a special film that can induce the overview effect. The space is darkened and the brain activity from the participant, while she is watching the movie in the gravity chair, is recorded and sent into space by Daniela, also a licensed radio amateur.’

‘Guillaume projects a mix of the live EEG-signals (the first two channels) on the Stellarium-view of the sky with the star Antares as starting point of the radio transmission and the spectrum of the transmission recorded with a small USB-antenna. The voice (the vowels) with call sign PI9CAM becomes visible in the jagged band, while the EEG transmission becomes visible as a dense continuous band. Meanwhile, the guests hear the transmission.’

– Update February 13, 2019

]]>Time-laps of the Earth appearing behind the Moonhttps://www.camras.nl/en/blog/2018/time-laps-of-the-earth-appearing-behind-the-moon/
Wed, 14 Nov 2018 09:32:43 +0000http://www.camras.nl/?p=3972On October 7, 2018, the Chinese lunar satellite DSLWP-B made this 1.5 hour time-lapse of the Earth appearing behind the Moon. An international team of radio amateurs and amateur astronomers downloaded the images with the Dwingeloo Radio Telescope. The team consisted of MingChuan Wei (BG2BHC), Reinhard Kuehn (DK5LA), Daniel Estévez (EA4GPZ/M0HXM), Tammo Jan Dijkema, Cees Bassa, Paul Boven (PE1NUT) and even more team members were involved. Click on the picture to see the time-lapse.

EME 2018 conference report

The EME 2018 conference was organized in the Netherlands in Hotel Zuiderduin in Egmond aan Zee. Organizers were Jan van Muijlwijk (PA3FXB) and his partner Marjan Pierhagen, both CAMRAS volunteers.

The program of the conference:

Thursday August 16, 2018 – Waterday with a visit to the Reeuwijkse Plassen, the Bergambacht ferry, and a harbour tour Rotterdam and Maasvlakte 2.

Friday August 17, 2018 – ASTRON day with a visit to the Westerbork Synthesis Radio Telescope, the Memorial Centre Westerbork (partners program), ASTRON and the Dwingeloo Radio Telescope and CAMRAS.

Saturday August 18, 2018 – Ham Radio Operators EME 2018 conference meeting, and partners program with visit to Alkmaar and Volendam.

Sunday August 19, 2018 – Ham Radio Operators EME 2018 conference meeting, and partners program with visit to the Royal Netherlands Sea Rescue Institution, the lighthouse, and the dunes.

In the fold menus below you can choose a contribution to the EME 2018 conference program. Once a fold menu topic is opened you can click on the picture to open the film registration of that topic.

The film registration of the contributions of the EME 2018 conference and the editing is done by Jan Klaassens and Henk Borg. You can find the 29 filmed EME 2018 conference topics also in the CAMRAS YouTube Channel.

– EME 2018 – ASTRON day with the Westerbork Synthesis Radio Telescope, ASTRON, and CAMRAS and the Dwingeloo Radio Telescope (Friday August 17, 2018)

Visit to CAMRAS and PI9CAM at the Dwingeloo Radio Telescope.

Jan PA0SSB – History of EME

In 1972 Jan PA0SSB made his own big dish and started doing EME. Jan will tell about these early days of EME and the way moonbounce was done back then.

Peter G3LTF - A survey of 6cm activity in 2018

Peter G3LTF – A survey of 6cm activity in 2018

Interest in 6cm EME has been growing steadily in the last decade. The paper will describe the characteristics of 6cm EME and the equipment used by stations both large and small with details of antennas, feeds, transmitters and receivers. Where possible the paper will reference sites with constructional details.

Bernd DL7APV - Building a 128 yagi array for 70 cm moonbounce

Bernd DL7APV – Building a 128 yagi array for 70 cm moonbounce

We all know in moonbounce bigger is better…

So Bernd DL7APV decided to build a huge yagi arry for 70 cm. Only a few months ago it was completed. It works as predicted but building it was hard work.

In this presentation Bernd will tell you all about it.

Zdenek OK1DFC - First ever 3 cm EME from Africa

Zdenek OK1DFC – First ever 3 cm EME from Africa

In October 2017 Zdenek OK1DFC activated Ceuta (EA9LZ) via the moon on 5 bands. Things did not work out totally as planned as the plan was to activate Morocco, but it turned out to be a very succesful expedition after all! Improvising and making the best of it were the keywords.

Zdenek will show several pictures and movies of the expedition.

Alex ZS6EME - UADC4, a dedicate ADC for SDR applications" the revival of ZERO IF receivers

Alex ZS6EME – UADC4, a dedicate ADC for SDR applications” the revival of ZERO IF receivers

The UADC4 is an ADC specially designed to work with SDR radios, specially with ZERO IF receivers, for many years we just use PC audio cards and this create a big obstacle because “Sound cards are for music” and not really specially designed for SDR applications, the performance of the UADC4 surpass the most expensive audio cards on the market for more than 10 dB’s and open a new window of experimentation for SDR radios based in IQ mixers were always was the sound card the limiting factor.

Sam G4DDK – The Iceni 70cm transverter

Iceni is the latest in a long line of G4DDK transverter designs going back to 1984 with the 4 and 6m Meons, through the 2m Suffolk, 23cm Kirton, 4m Nacton, and 2m Anglian 3. What was conspicuous by its absence was a 70cm transverter.

Having been asked if I would produce a design for 70cm, I began work in August 2017 on the design that would become the Iceni.

Although few could doubt that SDR transceiver architecture is the future, even for UHF through microwave, there is a still a steady interest in the superhet architecture transverter, for use with existing high performance HF rigs.

This paper describes the Iceni, the reasons for certain design decisions and the performance limitations that were felt acceptable.

As of spring 2018 more than 50 Iceni transverter kits have been produced and distributed.

This is the third chapter of our analyses of the effects on EME signals of ionosphere transit. We start with a short review on Moon reflection and depolarization. Then, using the excel sheet that we developed for modeling a full moon pass between two stations. we analyze 2 way polarization in VHF and UHF bands, and therefore qso probability for stations with linearly polarized antennas.

Moving from VHF to UHF, we show how the main factor in decode probability moves progressively from Faraday to Spatial Offset. We examine also the effect of axial rotation of the antenna.

John G4BAO - 5-band GHz EME from a European suburban garden

John G4BAO – 5-band GHz EME from a European suburban garden

Many people in general Amateur radio circles still think that EME requires huge dishes, QRO and a back garden the size of Switzerland.

This presentation follows the 10 – year journey taken by John, G4BAO from an interest in Microwave Terrestrial DX to completing EME QSOs from a suburban back garden on all five GHz bands up to and including 10GHz.

It covers the systems used and how they developed over the years, the limitations of such small systems and tips for optimising them to make QSOs “by any means.” It shows that with a “can do” attitude and a refusal to be told, “it’s not possible,” CW, JT mode and even SSB QSOs can be made from a small system by choosing the right bands, technologies, modes and QSO partners.

Neil G4LDR - Goonhilly - To the moon and back - GB6GHY

Neil G4LDR – Goonhilly – To the moon and back – GB6GHY

This is an account of EME operation from Goonhilly Earth Station in the UK during the summer of 2017. Initial, (unsuccessful), tests bouncing digital amateur television off the moon allowed access for ‘conventional EME’ operation. The 3.4 and 5.7GHz bands were used, where over 50 contacts were made. Measurements were also made to determine dish performance using the deep space radio source Taurus A.

Jan PA0PLY - 432MHz Polarisation Experiments

Jan PA0PLY – 432MHz Polarisation Experiments

Going the path on 432Mhz EME at a certain moment one realises that it becomes difficult to be able to work some stations for one reason. Little investigation shows actually, that there are much more than one reason involved in this phenomen.

With my presentation, I would like to share my experiments as well as the information found during my investigation and gathered in talks with yearlong experts on 432Mhz EME communication.

Jan PA0SSB - Comments on the new SSPA of the ON0EME moon beacon

Jan PA0SSB – Comments on the new SSPA of the ON0EME moon beacon

Joana DJ5YL - First YL EME SSB QSO on 70 cm

Joana DJ5YL – First YL EME SSB QSO on 70 cm

On May 27, 2017 Joana DJ5YL visited the radio telescope in Dwingeloo. The main goal was to have the first ever EME SSB YL QSO on 70 cm. The event was a big succes! Joana will tell you all about it.

Guy F2CT - The Tonna legacy

Guy F2CT – The Tonna legacy

I am both very moved and honoured to be speaking to you about Franck TONNA F5SE and his father Marc F9FT. I met them both in 1975 while I was a physics student.

Marc gave me 16 aerials of 9 elements that I put up in 1978 to carry out my first contacts in EME on 144Mhz. Many OM used the TONNA aerials from 50MHz to 2.3GHz. After taking an active part with his father in EME on 432MHz with a 16 x 21 elements TONNA, Franck went to get a 11 m satellite dish from F1JG in Arles, near Marseille. After completely taking it apart, he then put it back together at home, in Reims and adapted it on 1296MHz. His signals and echos via the moon were extremely powerful. He enjoyed getting in touch with his friends in SSB and singing the Brother Jacques song.

Rest In Peace Franck.

Hannes OE5JFL Nando I1NDP Mario I0NAA - Hunting for Pulsars

Hannes OE5JFL Nando I1NDP Mario I0NAA – Hunting for Pulsars

The detection of pulsars is one the most challenging and rewarding activity for an amateur radio station and facts are showing that amateurs well equipped for EME have good possibility to achieve this important result.

In 2016, after the WW EME conference in Venezia, a small “Euro Pulsar Working Group” with Andrea IW5BHY, Nando I1NDP, Hannes OE5JFL and Mario I0NAA was established exchanging experiences, information and best practices.

After few months, thanks to the software released by Andrea IW5BHY, all members of the group started to see the rst objects and Mario I0NAA released a program that allowed precise prediction of possibility of detection. Also, in order to avoid fake detections, the group established a peer-to-peer review process.

As of today, Hannes OE5JFL was able to detect more than 50 Pulsars and few months ago Nando I1NDP released new detection programs that allow to use high bandwidth SDR opening the door to even more challenging results.

In the presentation all details and results of this exciting journey will be given from the members of the group.

Harke PA0HRK - A beginners journey

Harke PA0HRK – A beginners journey

Many, many years ago I was inspired te become active with EME. However, the huge investment in equipment, the large antennasystem required and the necessary technical knowledge kept me on dreaming for many years. Until about 8 years ago when I learned that it would be very well feasible with modern technology. And that’s where my real journey started. Two years ago I made my first two QSO’s on 23cm in cw and last year my first 3cm QSO’s in QRA64, with (almost) completely home built equipment. I’d like to share with you some of my travel experiences, so as to inspire others.

Al K2UYH - SSB moonbounce

Al K2UYH – SSB moonbounce

Al is the founder of something we know as a Funtest.

Moonbounce is difficult. SSB moonbounce is even more difficult. But therefore a bigger challenge. Organising a contest for SSB moonbounce is really something special.

Al now will tell us all about it.

Hubert DJ3FI, Iban EB3FRN and Lou N2END - Table top presentations

Hubert DJ3FI, Iban EB3FRN and Lou N2END – Table top presentations

– N2END – A Microprocessor-Controlled Antenna Polarization System
An amateur-built system to control the polarization of Yagi-Uda antennas is described. The system makes use of a stepping motor and reduction drive to mechanically rotate an antenna boom along its axis. A microprocessor combines operator input, antenna position data, and time from an onboard clock and controls the stepping motor appropriately. Interaction with the operator is carried out with a simple command line interface. It allows the operator to adjust the receive position for best signal, and when available, the spatial polarization offset may be entered, from which the optimum transmit position is calculated. The microprocessor will automatically move the antenna between receive and transmit positions at the correct time. The antenna can move through an angle of 90 degrees in less than two seconds, allowing optimized linear polarization on both transmit and receive for typical modes used in EME communication. Polarization control was implemented in a 432 MHz EME system using homebuilt 15LFA-JT antennas with rear-mounted booms, and results obtained with it are described. A working prototype will be demonstrated during a tabletop presentation.

This image shows the far side of the Moon, as well as our own planet Earth. It was taken with a camera linked to an amateur radio transceiver on board the Chinese DSLWP-B / Longjiang-2 satellite (call sign BJ1SN), currently in orbit around the Moon, and transmitted back to Earth where it was received with the Dwingeloo Telescope.

This image represents the culmination of several observing sessions spread over the past few months where we used the Dwingeloo telescope in collaboration with the Chinese team from Harbin University of Technology, who build the radio transceiver on board Longjiang-2, and radio amateurs spread across the globe.

The transceiver on board Longjiang-2 was designed to allow radio amateurs to downlink telemetry and relay messages through a satellite in lunar orbit, as well as command it to take and downlink images. In that it has succeeded, as many radio amateurs have received telemetry and image data. Being able to use the Dwingeloo telescope to help with this has been a lot of fun.

This full color adjusted image is received by radio amateurs, including the radio amateurs of the Dwingeloo Radio Telescope (PI9CAM) operated by Tammo Jan Dijkema and myself. Commands were created by MingChuan Wei (BG2BHC) and uplinked by Reinhard Kuehn (DK5LA). The color correction of the image is done by Wei.

The annotated picture with names of Moon craters is made by Tammo Jan. Note that the crater Minnaert is named after the Dutch astronomer Marcel Minnaert. Minnaert was member of the SRZM board in the time the Dwingeloo Radio Telescope was designed and build.

Addendum after October 12, 2018

Below are two other images, also slightly color corrected. The original images are here. The third image shows the Moon clearly seen from Dwingeloo Radio Telescope through the window of the observation room and the metal mesh of the mirror.

The animation below shows the Moon as seen from the DSLWP-B satellite as it orbits around the Moon. The animation pictures were taken on October 15. Data for the animation was collected by Cees Bassa and Tammo Jan Dijkema in the Dwingeloo Telescope (PI9CAM), by Imants Tukleris (YL3CT), Mike Rupprecht (DK3WN), and Dimitry Borzenko (4Z5CP). The satellite was commanded by Reinhard Kuehn (DK5LA).

Update February 4, 2019

After a radio-quiet period to avoid interfering with the Chang’e 4 Lunar landing, DSLWP-B became active again on 13 January 2019. The first opportunity to take photos of Earth and Moon were on 3 February, on which a command was sent to take another timelapse. The first image from this timelapse was downloaded with the Dwingeloo telescope on February 4, 2019. For the first time, it the entire Moon and Earth are in view.

In advance in December 2017

December 2017, in preparation for the mission and discussion of the possibilities of the antennas and receivers in the radio telescope, Hu Chaoran (BG2CRY) and MingChuan Wei (BG2BHC) both of the Harbin Institute of Technology visited Harry Keizer (PE1CHQ) and Jan van Muijlwijk (PA3FXB) of CAMRAS. On the photo in front of the Dwingeloo Radio Telescope to the left Jan, in the middle Chaoran, and to the right Wei. In fact the Dwingeloo dish is transparent metal mesh, but on this winter photo covered with snow.

]]>Dwingeloo has fringes (again) !https://www.camras.nl/en/blog/2018/dwingeloo-has-fringes-again/
Fri, 31 Aug 2018 14:29:40 +0000http://www.camras.nl/?p=3395On Wednesday the 29th of August 2018, the Dwingeloo Radio Telescope took part in a test VLBI observation and we managed to obtain fringes to Westerbork and Jodrell Bank (Mark II Radio Telescope) right away. This is more than 40 years after its first appearance as a VLBI telescope (see Schilizzi e.a., A&A 77, 1979).

The Dwingeloo Telescope, once the largest fully steerable dish in the world, is now operated by the CAMRAS volunteer organisation. They have, with great support from ASTRON, restored and rejuvenated the historical instrument. Its return to VLBI is a huge milestone and a testament to the great work by all these volunteers.

The image shows the fringes in one of the 8 subbands of each 16 MHz that were recorded. The background image depicts the ‘flowchart’ created in the open source GnuRadio program to convert the input from raw samples, into properly timestamped VDIF data for the JIVE correlator.

Just like the previous time that Dwingeloo did VLBI, the frequency reference is again a borrowed Rubidium clock. However, as part of the ASTERICS project, we are working to transport the H-maser frequency reference signal from Westerbork over fiber to the Dwingeloo Telescope. This still requires a bit of digging to bridge the last few hundred meters to the telescope, but expect even better fringes soon.